In order to combine power generated from two or more independent input voltage or energy sources to generate a regulated DC output voltage, numerous topologies of multiple-input power converters have been proposed in recent years. The independent input voltage or energy sources may for example comprise clean energy sources such as solar arrays, wind turbines, fuel cells, batteries and commercial ac power lines. A common limitation of some known multiple-input power converters is that only a single input voltage or power source is allowed to transfer power or energy to the converter output at a time to prevent power coupling effects. These power coupling effects may introduce circulating currents in a primary side of a power converter transformer and its associated input driver circuitry. These power coupling effects therefore induce considerable power loss in the primary side of the power converter transformer and its associated input driver circuitry and may seriously damage the driver circuitry. The present invention proposes new circuit topologies for single input and multiple-input isolated power converters using separate multiple-winding transformers with a novel winding connection of secondary side half-windings. The idea behind the present invention origins from the isolated power converter topologies described in the present applicant's published PCT patent application WO2013/037696 “An integrated magnetics component” relating to a novel four quadrant integrated transformer (FQIT) for single input or multiple-input power converters. The FQIT based power converter topologies enable full decoupling between multiple primary or input side inductor windings of the transformer assembly such that two separate input power sources are allowed to transfer energy into a converter output simultaneously or at any time-multiplexing scheme without undesired power coupling effects.
The present invention provides in one aspect a novel integrated magnetics transformer assembly which is electrically equivalent to the FQIT despite possessing a markedly different magnetic core geometry. Despite the considerable number of advantages offered by power converters based on the FQIT core geometry, it remains at present a customized structure which may require specialized manufacturing tooling. In contrasts, the present integrated magnetics transformer assembly may be based on two magnetically permeable cores of conventional core geometry such as the E-shape. These traditional core geometries are readily available from numerous sources and at low cost. Furthermore, the equivalent circuit structure of the present integrated magnetics transformer assembly enables a convenience on the electrical analysis and simulation together with a straightforward understanding of operational principles of power converters based on the present integrated magnetics transformer assembly.